The present invention relates to using a new brominated epoxy resin for processing glass fiber laminate with proper reactivity, broad working window and good operation, from which the obtained laminate substrate features high Tg and heat resistant property; it applies to electronic material with high performance.
People are more and more demanding the electrical material with high performance along with printed circuit board has been developed in light, thin, miniaturization and sophistication way. The value of Tg is a very useful indicator to normal material, which represents the level of withstanding dynamic stress in certain temperature such as vibration, high temperature, etc. If the temperature of material is higher than Tg, it would results in poor interlayer bonding, and furthermore lowering adhering strength of copper foil, thus it is an important subject matter and trend to develop a glass fiber laminate with high Tg and heat resistance.
Now, FR-4 substrate which is available in market is made of double functional brominated epoxy resin, Tg value is at 130xcx9c140xc2x0 C., and the method of raising Tg value is to mix multifunctional epoxy resins such as o-cresol formaldehyde novolac epoxy, tetra functional epoxy, phenol novolac epoxy, etc., although Tg value can be raised by the above-mentioned resins and with good heat resistance, but when hardening to be done with usual hardening agent of dicyandiamide, it causes gel time faster and working window narrower. It has to be required to strictly control process in order to avoid substandard product, therefore it often influences the yield of qualified product and output capacity.
To solve operation problem of processing glass fiber laminate caused by the above-mentioned multifunctional epoxy resin such as o-cresol formaldehyde novolac epoxy, tetra functional epoxy and phenol novolac epoxy, the goal of the present invention is to provide a new brominated epoxy resin with proper reactivity, broad working window and good operation performance, high Tg, heat resistance, electricity, fire resistance and low moisture absorbance.
The present invention relates to brominated epoxy resin, which consists of (A) multifunctional phenol-benzaldehyde epoxy resin (formula 1), (B) difunctional epoxy, (C) difunctional bromine-containing epoxy resin and (D) tetrabromobisphenol-A. 
is obtained by synthesis. When the synthesis is processed, it is to take (D) tetrabromobisphenol-A to react with at least one of (A),(B)and (C) (including one kind), after that the rest of (A),(B)and(C) are added and mixed, then a new brominated epoxy resin produced.